Problem: Solve for $p$ : $30 = 26 + p$
Solution: Subtract $26$ from both sides: $ \begin{eqnarray} \\ \hphantom{30 {- 26}} &\hphantom{=}& \hphantom{p} \\ 30 &=& 26 + p \\ \\ {-26} && {-26} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 30 {- 26} &=& p \\ \end{eqnarray} $ Simplify. $ p = 4$